Model: YC4108
Part Number: B8800-1005001B
Brands: Yuchai
Engine Model: YC4108
Engine Type: Diesel
Scope of application: light and medium trucks, agricultural machinery, generator sets, marine auxiliary
The Yuchai YC4108 is a four-cylinder diesel that works in trucks, agricultural machinery and generator sets across Southeast Asia, Africa and Latin America. Part B8800-1005001B is the crankshaft for this engine, carrying four connecting rods and driving the camshaft and oil pump through the front gear train.
A four-cylinder engine fires twice per revolution, so the torque curve is less smooth than a six. The crankshaft absorbs that irregularity along with bending loads from each power stroke. Journal condition decides how long the engine lasts after a rebuild.
The shaft fits YC4108 engines across their ratings. Confirm the engine plate and the old crankshaft number before ordering. Yuchai built the 4108 in variants with different front pulley and flywheel arrangements.
Shafts ship in a braced carton with journals sleeved. Tell us before dispatch if you need an undersize.
A knock is the last warning before a bearing spins, and by then the journal is usually already damaged.
Match the part number, the journal size and the shells you intend to fit. Mixing a reground shaft with standard shells guarantees failure. Give us the bearing part numbers and we will confirm the journal size before shipping.
Many YC4108 engines work in dusty agricultural conditions with modest oil change discipline. Dust reaching the oil acts as an abrasive on the journals, and the first sign is a polished or scored bearing surface long before a knock appears. Regular oil analysis would catch it far earlier than the ear.
A four-cylinder crankshaft sees strong torsional pulses. The damper absorbs them; when its rubber perishes, the pulses reach the shaft and cracks begin at the fillets. Inspect the damper whenever the shaft is out, and replace it with a new shaft as a matter of course.
Shafts are heavy, so they are braced in a carton or crated with lifting points marked. Freight is charged on weight and volume, so tell us whether the shaft travels with a block so we can plan the load.
Lubrication and vibration control decide crankshaft life. Use the specified oil, change it at the severe-duty interval and never run with a leaking injector that thins the oil. After a hydraulic lock or a broken damper, check straightness before reuse.
Main and rod shells are supplied in standard and undersize grades. The grade must match the journal after any regrind, and the only reliable way to confirm the match is to measure the journal, not to trust the marking on the box. On a used engine, one journal may already have been ground by a previous rebuilder.
Check clearance with plastigauge at every journal and record the figures. On a four-cylinder engine there are only five mains and four rods, so the measurements take little time and they turn a hopeful assembly into a documented one.
Before the crankshaft goes in, confirm main bore alignment with a line bore check. A distorted tunnel wears new bearings within hours, and the shaft is usually blamed. Check the thrust faces for scoring and confirm that gallery plugs are fitted and sealed.
New crank seals only work if the surfaces they run on are undamaged. Inspect the front pulley hub and the rear flange for a groove worn by the old seal. A deep groove lets oil past even with a new seal, and the leak is then blamed on the seal or on the crankshaft itself.
If the groove is significant, either fit a speed sleeve or replace the shaft. On an export rebuild, replacing the shaft is usually the cleaner answer because a leak discovered at sea cannot be fixed at anchor.
Yes, supplied with standard journals. Undersize shafts are available on request.
Only if enough hardened layer remains. Most buyers prefer a new shaft.
Strongly recommended with a new shaft.
Mount on centres and measure run-out at the centre journal.
Explore the Yuchai crankshaft category, and complete the bottom end with the YC4108 connecting rod A8300-1004200 or the YC4108 oil pump D30-1011100.
Yuchai YC4108 Crankshaft (1005001). The crankshaft converts combustion pressure into torque and carries the entire load of the rotating assembly. Its journals set the oil film that keeps the bearings alive.
Measure ovality at several positions along each journal, not at one point. A journal can read the correct diameter and still be oval by a few hundredths, which collapses the oil film twice per revolution.
Numbers beginning 1005 appear on WP8 and WP9 assemblies. Because the series was introduced to simplify supersessions, several older numbers map onto it. On this engine, confirm the YC4108 application against the engine plate before ordering.
Ask the machine shop explicitly whether the fillet radius has been restored, and to what value. Fatigue cracks start at the journal-to-web transition, and a sharp corner from grinding is where they begin.
Ordering note. If the old number has been superseded, the replacement number is quoted alongside the original so the purchasing file stays consistent.
Related reading: Crankshaft Inspection: Journals, Fillets and Regrinding
| We Are 30 Years Diesel Engine Parts Supplier | |
| Brand | EPID |
| Warranty | 12 Months |
| Condition | 100%New |
| More Models | Weichai: YC4108, and other Weichai series. |
| Shipping | By sea / air / express (DHL, FEDEX, TNT, UPS, EMS) |
| Packing | Standard exporting packing or as required |
| Payment Term | L/C, T/T, Western Union, Trade Assurance |
| Delivery Time | 3-7 days (depend on order) |
| Selling Point | 1. On-time Delivery 2. Genuine Quality Assurance 3. Professional Supplier |
Shafts ship in a braced carton with journals sleeved. Tell us before dispatch if you need an undersize.
A knock is the last warning before a bearing spins, and by then the journal is usually already damaged.
Match the part number, the journal size and the shells you intend to fit. Mixing a reground shaft with standard shells guarantees failure. Give us the bearing part numbers and we will confirm the journal size before shipping.
Many YC4108 engines work in dusty agricultural conditions with modest oil change discipline. Dust reaching the oil acts as an abrasive on the journals, and the first sign is a polished or scored bearing surface long before a knock appears. Regular oil analysis would catch it far earlier than the ear.
A four-cylinder crankshaft sees strong torsional pulses. The damper absorbs them; when its rubber perishes, the pulses reach the shaft and cracks begin at the fillets. Inspect the damper whenever the shaft is out, and replace it with a new shaft as a matter of course.
Shafts are heavy, so they are braced in a carton or crated with lifting points marked. Freight is charged on weight and volume, so tell us whether the shaft travels with a block so we can plan the load.
Lubrication and vibration control decide crankshaft life. Use the specified oil, change it at the severe-duty interval and never run with a leaking injector that thins the oil. After a hydraulic lock or a broken damper, check straightness before reuse.
Main and rod shells are supplied in standard and undersize grades. The grade must match the journal after any regrind, and the only reliable way to confirm the match is to measure the journal, not to trust the marking on the box. On a used engine, one journal may already have been ground by a previous rebuilder.
Check clearance with plastigauge at every journal and record the figures. On a four-cylinder engine there are only five mains and four rods, so the measurements take little time and they turn a hopeful assembly into a documented one.
Before the crankshaft goes in, confirm main bore alignment with a line bore check. A distorted tunnel wears new bearings within hours, and the shaft is usually blamed. Check the thrust faces for scoring and confirm that gallery plugs are fitted and sealed.
New crank seals only work if the surfaces they run on are undamaged. Inspect the front pulley hub and the rear flange for a groove worn by the old seal. A deep groove lets oil past even with a new seal, and the leak is then blamed on the seal or on the crankshaft itself.
If the groove is significant, either fit a speed sleeve or replace the shaft. On an export rebuild, replacing the shaft is usually the cleaner answer because a leak discovered at sea cannot be fixed at anchor.
Explore the Yuchai crankshaft category, and complete the bottom end with the YC4108 connecting rod A8300-1004200 or the YC4108 oil pump D30-1011100.
Yes, supplied with standard journals. Undersize shafts are available on request.
Only if enough hardened layer remains. Most buyers prefer a new shaft.
Strongly recommended with a new shaft.
Mount on centres and measure run-out at the centre journal.
EPID supplies diesel engine parts for Weichai, Baudouin, Yuchai, Caterpillar, Sinotruk, FAW Xichai and Cummins engines. Every order is checked against the original part number before packing, and our team can identify a part from a photo of the engine plate. Ask for a quotation with your model and quantity and we will reply within one working day.
